Functional textiles such as outer clothing worn for protection against moisture from the air gradually lose their water-repelling property, their impregnation, during use. This property can be restored by applying a hydrophobic substance to the textile fibers. In general, this textile treatment is carried out in an industrial laundry or a cleaning business. However, there is an increasing desire for such treatments to be carried out in a domestic washing machine.
Hydrophobizing agents suitable for use in domestic washing machines for impregnating textiles are therefore being provided in the relevant trade. Such agents predominantly consist of fluorocarbon resins or paraffin-containing agents. The impregnation is then conducted in a known manner in a standard washing process in a so-called long wash that includes a relatively large amount of washing liquid per kg of laundry is used. A recommended dose of hydrophobic active substance is poured into the main wash compartment of a detergent flushing-in device before the beginning of this standard washing process and is supplied together with cold fresh water to the tub of the washing machine. The impregnating solution is brought in contact with the laundry during movement of the laundry by rotating the laundry drum whilst it is heated in the tub by means of a heating device. The duration of this treatment is predefined by the program of the washing machine controller which, among other things, is determined by reaching the predetermined temperature of the impregnating solution. At the end of the washing process, the laundry is rinsed several times so that the quantity of impregnating agent absorbed on the textile fibers of the laundry is reduced again. Thus, the hydrophobic effect which can be achieved by the known method is relatively small.